Zirconium oxide nanoparticles with 0.4 wt.%and 0.8 wt.%are incorporated into the Al-0.65 Mg-0.05 Ga-0.15 Sn(wt.%)alloy anode(base alloy)in order to improve the performance of the resulting anodes.Electrochemical chara...Zirconium oxide nanoparticles with 0.4 wt.%and 0.8 wt.%are incorporated into the Al-0.65 Mg-0.05 Ga-0.15 Sn(wt.%)alloy anode(base alloy)in order to improve the performance of the resulting anodes.Electrochemical characterization of the reinforced alloys was done by potentiodynamic polarization,electrochemical impedance spectroscopy and galvanostatic discharge and corrosion behavior was evaluated using self-corrosion rate and hydrogen evolution in 4 mol/L KOH solution.The surface morphology of the alloys was also studied using field emission scanning electron microscope(FESEM).The obtained results indicate that the base alloy shows high corrosion rate in 4 mol/L KOH solution by releasing 0.47 m L/(min·cm^2)hydrogen gas,whereas the alloy containing 0.8 wt.%Zr O2 provides the lowest hydrogen evolution rate by releasing 0.32 m L/(min·cm^2)hydrogen gas.Furthermore,by increasing zirconium oxide nanoparticles,the corrosion current density of the aluminum anodes is decreased and their corrosion resistance increases significantly compared to the base alloy in alkaline solution.In addition,nanometer-sized zirconium oxide incorporated anodes exhibit the improved galvanic discharge efficiencies,so that 0.8 wt.%nano-zirconium oxide incorporated base alloy displays the highest power density and anodic utilization compared with the others in 4 mol/L KOH solution.展开更多
ZnFe 2O 4 and ZnFe 2O 4 based materials were tested to obtain the electrical conductivity and corrosion resistance in melting bath for aluminum electrolysis. The results proved that adequate additives, such as Ni 2O 3...ZnFe 2O 4 and ZnFe 2O 4 based materials were tested to obtain the electrical conductivity and corrosion resistance in melting bath for aluminum electrolysis. The results proved that adequate additives, such as Ni 2O 3 CuO, Cu, ZnO and CeO 2 would increase the electrical conductivity, and the ZnFe 2O 4 based anodes with these additives were of good corrosion resistance. The current density on anode, the mole ratio of NaF/AlF 3 (MR) and the content of alumina in the bath effect the anode corrosion rate in different way.展开更多
A systematic laboratory study was conducted on current efficiency and corrosion obtained in cryolite-alumina melts with SnO2-Sb203-CuO ceramic inert anodes. The current efficiency （CE） was determined by measuring th...A systematic laboratory study was conducted on current efficiency and corrosion obtained in cryolite-alumina melts with SnO2-Sb203-CuO ceramic inert anodes. The current efficiency （CE） was determined by measuring the total amount of oxygen evolved at the anode and was found to be ~ 95%. The influence of operating parameters （inter-elec- trode distance, temperature and current density） was evaluated. The quantitative interdependencies as well as the ranges of CE optima[ values were established （2-3 cm, 940-960 ℃ and 0.7-0.8 A.cm 2）. The corrosion process of these anodes was evaluated by the mass loss method. The evaluation also took care of the corrosion data, as the prob- lem of the anode corrosion appeared to be the main obstacle for the use of those anodes in the commercial cells.Low-ering of the ACD up to 2 cm did not aggravate anode corrosion.展开更多
Numerical simulations of gas–liquid two-phase flow and alumina transport process in an aluminum reduction cell were conducted to investigate the effects of anode configurations on the bath flow, gas volume fraction a...Numerical simulations of gas–liquid two-phase flow and alumina transport process in an aluminum reduction cell were conducted to investigate the effects of anode configurations on the bath flow, gas volume fraction and alumina content distributions. An Euler–Euler two-fluid model was employed coupled with a species transport equation for alumina content. Three different anode configurations such as anode without a slot, anode with a longitudinal slot and anode with a transversal slot were studied in the simulation. The simulation results clearly show that the slots can reduce the bath velocity and promote the releasing of the anode gas, but can not contribute to the uniformity of the alumina content. Comparisons of the effects between the longitudinal and transversal slots indicate that the longitudinal slot is better in terms of gas–liquid flow but is disadvantageous for alumina mixing and transport process due to a decrease of anode gas under the anode bottom surface. It is demonstrated from the simulations that the mixing and transfer characteristics of alumina are controlled to great extent by the anode gas forces while the electromagnetic forces(EMFs) play the second role.展开更多
AlNbO_4,as lithium-ion batteries（LIBs） anode,has a high theoretical capacity of 291.5 m Ah g^-1.Here,AlNbO_4 anode materials were synthesized through a simple solid-state method.The structure,morphology and electroc...AlNbO_4,as lithium-ion batteries（LIBs） anode,has a high theoretical capacity of 291.5 m Ah g^-1.Here,AlNbO_4 anode materials were synthesized through a simple solid-state method.The structure,morphology and electrochemical performances of AlNbO4 anode were systematically investigated.The results show that AlNbO4 is monoclinic with C2/m space group.The scanning electron microscopy（SEM） and transmission electron microscopy（TEM） characterizations reveal the AlNbO_4 particles with the size of 100 nm^–2 lm.As a lithium-ion batteries anode,AlNbO4 delivers a high reversible capacity and good rate capability.The discharge capacity is as high as 151.0 m Ah g^-1 after 50 charge and discharge cycles at 0.1 C corresponding to capacity retention of 90.7 %.When the current density increases to 5.0C,AlNbO4 anode displays reversible discharge capacity of 73.6 m Ah g^-1 at the50 th cycle.展开更多
According to dynamics of coupled galvanic anode with carbon steel,the integral of galvanic current vs.time is approximately equal to actual current capacity of galvanic anode.Galvanic current of cast aluminum galvanic...According to dynamics of coupled galvanic anode with carbon steel,the integral of galvanic current vs.time is approximately equal to actual current capacity of galvanic anode.Galvanic current of cast aluminum galvanic anode coupled with carbon steel is tested in3.5%NaCl solution and ambient temperature.Rapid evaluation the performance of galvanic anode using galvanic current is feasible,and the test time is20min.The galvanic current is used to select aluminum galvanic anodes in oil brine,and then test the galvanic anodes with impressed current test method.The result shows,the performance of galvanic anodes degrads in oil brine,but has not much difference in the two media to the preferable anodes,and the optimal galvanic anode is gained.展开更多
In order to evaluate the electrochemical properties of aluminum alloy anode under high current densities in alkaline electrolyte, the galvanostatic discharge, potentiodynamic polarization and hydrogen evolution tests ...In order to evaluate the electrochemical properties of aluminum alloy anode under high current densities in alkaline electrolyte, the galvanostatic discharge, potentiodynamic polarization and hydrogen evolution tests of three experimental Al?Mg?Sn?In?(Ga) alloys were performed. The results show that the alloying element gallium improves the working potentials of experimental Al?Mg?Sn?In alloys under different discharge current densities. The average working potentials of the alloys containing gallium can reach?1.3 V under current density ranging from 650 to 900 mA/cm2, while those of alloy without Ga are only?1.0 V. Such phenomenon is attributed to the solid solution which can form amalgam with aluminum matrix. Such an amalgam can form the hydrolyzed species during the discharge process and lead to the corrosion infiltrating into aluminum matrix.展开更多
The effect of intermetallic particles on the corrosion of 6061 aluminum alloy and its coating used in semiconductor processing systems was systematically studied via liquid and gas experiments and micromorphology char...The effect of intermetallic particles on the corrosion of 6061 aluminum alloy and its coating used in semiconductor processing systems was systematically studied via liquid and gas experiments and micromorphology characterization.The results revealed that a huge difference of corrosion resistance between imported and domestic 6061 aluminum alloys in HCl solution and gas acid mist experiments mainly was attributed to the different size and amount of Al_(15)(Fe,Mn)_(3)Si_(2).The corrosion resistance of domestic 6061 alloy in dry/wet semiconductor electronic special gas environments was worse than that of imported aluminum alloy,and there are great differences in the corrosion mechanism of 6061 alloy caused by the second phase in the two dry/wet environments.And the corrosion resistance of the hard anodized alumina film was closely related to the microscopic morphology of holes.The vertical and elongatedα-Al_(15)(Mn,Fe)_(3)Si_(2) phase was formed in the rolled aluminum alloy that has been rolled perpendicular to the surface of the substrate.Compared to the horizontal long hole,the longitudinal long holes generated by the verticalα-Al_(15)(Mn,Fe)_(3)Si_(2) phase will enable the corrosive medium to reach the substrate rapidly,which significantly weakens the corrosion resistance of the hard anodized film.展开更多
A principle was proposed for designing a method to seal anodized aluminum used in semiconductor processing apparatuses.Thermodynamic calculations and Fick’s second law were used to reveal trends in the metal ion depo...A principle was proposed for designing a method to seal anodized aluminum used in semiconductor processing apparatuses.Thermodynamic calculations and Fick’s second law were used to reveal trends in the metal ion deposition,deposition product stability,vapor pressures of halides for selected metal ions,the holding temperature,and time.Interactions between ion concentrations and the sealing temperature were also revealed.According to the design principles,anodized aluminum dipped in 1 mM Cr^(3+)ion solution and steam-sealed for 18 h exhibited the highest corrosion resistance when exposed to 5 wt.%HCl solution and HCl gas,verifying the designed results.展开更多
The aluminum-air battery is considered to be an attractive candidate as a power source for electric vehicles(EVs) because of its high theoretical energy density(8100 Wh kg^(-1)), which is significantly greater than th...The aluminum-air battery is considered to be an attractive candidate as a power source for electric vehicles(EVs) because of its high theoretical energy density(8100 Wh kg^(-1)), which is significantly greater than that of the state-of-the-art lithium-ion batteries(LIBs). However,some technical and scientific problems preventing the large-scale development of Al-air batteries have not yet to be resolved. In this review, we present the fundamentals, challenges and the recent advances in Al-air battery technology from aluminum anode, air cathode and electrocatalysts to electrolytes and inhibitors. Firstly, the alloying of aluminum with transition metal elements is reviewed and shown to reduce the selfcorrosion of Al and improve battery performance. Additionally for the cathode, extensive studies of electrocatalytic materials for oxygen reduction/evolution including Pt and Pt alloys, nonprecious metal catalysts, and carbonaceous materials at the air cathode are highlighted.Moreover, for the electrolyte, the application of aqueous and nonaqueous electrolytes in Al-air batteries are discussed. Meanwhile, the addition of inhibitors to the electrolyte to enhance electrochemical performance is also explored. Finally, the challenges and future research directions are proposed for the further development of Al-air batteries.展开更多
Aluminum(Al) metal has been regarded as a promising anode for rechargeable batteries because of its natural abundance and high theoretical specific capacity. However, rechargeable aluminum batteries(RABs) using A1 met...Aluminum(Al) metal has been regarded as a promising anode for rechargeable batteries because of its natural abundance and high theoretical specific capacity. However, rechargeable aluminum batteries(RABs) using A1 metal as anode display poor cycling performances owing to interface problems between anode and electrolyte. The solid-electrolyte interphase(SEI) layer on the anode has been confirmed to be essential for improving cycling performances of rechargeable batteries. Therefore, we immerse the Al metal in ionic liquid electrolyte for some time before it is used as anode to remove the passive film and expose fresh Al to the electrolyte. Then the reactions of exposed Al, acid, oxygen and water in electrolyte are occurred to form an SEI layer in the cycle. Al/electrolyte/V_2 O_5 full batteries with the thin, uniform and stable SEI layer on Al metal anode perform high discharge capacity and coulombic efficiency(CE). This work illustrates that an SEI layer is formed on Al metal anode in the cycle using a simple and effective pretreatment process and results in superior cycling performances for RABs.展开更多
Aluminum(Al),the most abundant metallic element on the earth crust,has been reckoned as a promising battery material for its the highest theoretical volume capacity(8046 mAh cm^(-3)).Being rechargeable in ionic liquid...Aluminum(Al),the most abundant metallic element on the earth crust,has been reckoned as a promising battery material for its the highest theoretical volume capacity(8046 mAh cm^(-3)).Being rechargeable in ionic liquid electrolytes,however,the Al anode and battery case suffer from corrosion.On the other hand,Al is irreversible in aqueous electrolyte with severe hydrogen evolution reaction.Here,we demonstrate a water-in-salt aluminum ion electrolyte(WISE)based on Al and lithium salts to tackle the above challenges.In the WISE system,water molecules can be confined within the Li^(+)solvation structures.This diminished Al^(3+)-H_(2)O interaction essentially eliminates the hydrolysis effect,effectively protecting Al anode from corrosion.Therefore,long-term Al plating/stripping can be realized.Furthermore,two types of high-performance full batteries have been demonstrated using copper hexacyanoferrate(CuHCF,a Prussian Blue Analogues)and LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM)as cathodes.The reversibility of Al anode laid the foundation for low cost rechargeable batteries suffering for large-scale energy storage.Broader context:Al batteries are expected to become a safe and sustainable alternative to lithium batteries.For decades,chase for a feasible Al secondary battery has not been successful.The key challenge is to find suitable cathode and electrolyte materials,together with which Al anode battery can function reversibly.Currently,fatal drawbacks have impeded the practical application of Al metal batteries(AMBs),such as sustained corrosion of Al anode and battery case in ionic liquid electrolytes,irreversibility issues as well as severe hydrogen evolution reaction during cycling in aqueous electrolyte.Therefore,electrolyte and their electrochemical kinetics play a vital role in the performance and environmental operating limitations of high-energy Al metal batteries.In this work,we demonstrate a nearly neutral Al ion water-in-salt electrolyte(WISE)to tackle the above challenges.The WISE shows excellent stability in the open atmosphere.The distinct solvation-sheath structure of Al^(3+)in the WISE system would protect Al metal anodes from corrosion and eliminate hydrogen evolution reaction effectively,further promoting the reversibility of Al metal anodes with dendrite-free morphology.Moreover,such a WISE exhibits superior compatibility with LiNi_(0.3)Co_(0.3)Mn_(0.3)O_(2)(NCM)and copper hexacyanoferrate(CuHCF)cathodes and long-term stabilities with high coulombic efficiency(CE)can be attained for full batteries with the WISE.The approach in this study can furnish an opportunity to develop reversible AMBs and lay the foundation for other potential multivalent-metalbased secondary batteries suffering from interface passivation and poor reversibility,which suggest the promise of multivalent metal batteries and their applications in large-scale energy storage.展开更多
The growing market for electric vehicles and upcoming grid-scale storage systems is spurring the development of renewable energy storage technologies.Rechargeable aqueous aluminum-ion batteries(AIBs)are considered ide...The growing market for electric vehicles and upcoming grid-scale storage systems is spurring the development of renewable energy storage technologies.Rechargeable aqueous aluminum-ion batteries(AIBs)are considered ideal for large-scale energy storage because of their cost-competitiveness,simplicity of manufacturing,eco-friendliness,high intrinsic safety,and high theoretical energy density.In addition,AIBs use aluminum as a raw material,which is the most abundant metal in the Earth’s crust.However,metallic aluminum anodes exhibit poor thermodynamic stability in solutions because of self-corrosion,surface passivation,and hydrogen precipitation reactions.These factors considerably limit their electrochemical performance and impede the further development of AIBs.This review discusses the recent advances in the anode materials used in AIBs.We first briefly describe the energy storage mechanisms and challenges faced by various AIB anodes,including aluminum metal anodes,alloy anodes,and intercalated anodes.Subsequently,we summarize the interactions between the structures and reaction mechanisms of different anode materials,which have been used to prevent the passivation and corrosion of metallic aluminum anodes.Finally,we present the key challenges and future research perspectives for optimizing aluminum anodes to enhance the performance of AIBs.展开更多
Fe nanowire arrays are prepared by electrodeposition in porous anodic aluminum oxide template from a composite electrolyte solution. These nanowires have an uniform diameter of approximate 25 nm and a length in excess...Fe nanowire arrays are prepared by electrodeposition in porous anodic aluminum oxide template from a composite electrolyte solution. These nanowires have an uniform diameter of approximate 25 nm and a length in excess of 2.5 μm. The micrographs and crystal structures of Fe nanowires are studied by transmission electron microscopy (TEM), selected-area electron diffraction (SAED), and X-ray diffraction(XRD). It is found that each nanowire is essentially a single crystal and has a different orientation in each array. Hysteresis loops of Fe nanowire array show that its easy magnetization direction is perpendicular to the sample plane.展开更多
The rare earth sealing procedure of the porous film of anodized aluminum alloy 2024 was studied with the fieldemission scanning electron microscope (SEM) and X-ray energy dispersive spectroscopy (EDS). The results sho...The rare earth sealing procedure of the porous film of anodized aluminum alloy 2024 was studied with the fieldemission scanning electron microscope (SEM) and X-ray energy dispersive spectroscopy (EDS). The results show thatRE solution can form cerium oxide/hydroxides precipitation in the pores of the anodized coating at the beginning ofsealing. At the same time, the spherical deposits formed on the surface of the anodized coating created a barrierto the precipitation of RE solution in the pores. When the pore-structured anodizing film is covered all with thespherical deposits, RE conversion coating will form on the surface of the anodized coating. The reaction of thecoating formation was investigated by employing cyclic voltammetry. The results indicate that accelerator H2O2 actsas the source of O2 by carrying chemical reaction in course of coating formation. In the mean time, it maybe carrieselectrochemical reaction to generate alkaline condition to accelerate the coating formation. The porous structure ofthe film is beneficial to the precipitation of the cerium hydroxides film.展开更多
Aluminum specimens were anodized in a sulfuric acid bath, thensilver was electrodeposited in pores of the anodized aluminum byusing alternating current. The anodized aluminum with depositedsilver was tested for its an...Aluminum specimens were anodized in a sulfuric acid bath, thensilver was electrodeposited in pores of the anodized aluminum byusing alternating current. The anodized aluminum with depositedsilver was tested for its antibacterial performance. The results showthat the antibacterial rates of the specimens are above 95/100against the growth of E. coli, P. Aeruginasa, S. faecalis and S.aureus. The morphology of the silver in pores of anodized aluminum ischaracterized by transmission electron microscopy, and themicrographs indicate that silver is assembled in the form ofnanowires with a diameter of 10 nm or 25 nm. The nanowires have astructure of parallel bright stripes alternating with parallel darkstripes.展开更多
A new Fe Pt nanostructure with stripe-like patterns has been prepared by direct current（DC） magnetron sputtering on anodic aluminum oxide（AAO） templates. AAO templates anodized under low voltages（7 V） demonstrat...A new Fe Pt nanostructure with stripe-like patterns has been prepared by direct current（DC） magnetron sputtering on anodic aluminum oxide（AAO） templates. AAO templates anodized under low voltages（7 V） demonstrate self-organized,maze-like patterns, different from the conventional porous structures obtained at high voltages. Fe Pt thin films deposited on such templates tend to replicate the morphology of the templates. Although there is no obvious spatial ordering, the dimensions of the Fe Pt nano-stripes are highly uniform, due to the constrained growth along the transverse direction of the AAO pattern. The magnetic properties are strongly influenced by this unique morphology. While continuous films demonstrate strong exchange coupling, the dominant interaction in Fe Pt nano-stripes with the same nominal thickness is magnetostatic. The morphology also dictates the magnetization reversal behaviors, with thin films dominated by domain nucleation; while nano-stripes incline to reverse their magnetization by spin rotation. Our work demonstrates that selforganized AAO templates can be used to control the morphology and magnetic behavior of Fe Pt materials.展开更多
A simple, cost effective and rapid electrochemical method has been developed for the determination of micro level ortho nitrobenzaldehyde（ONB） based on outstanding properties of modified aluminum electrode tin nanor...A simple, cost effective and rapid electrochemical method has been developed for the determination of micro level ortho nitrobenzaldehyde（ONB） based on outstanding properties of modified aluminum electrode tin nanorods/anodic aluminum oxide/aluminum（SnNR/AAO/Al） for the first time. The SnNR/AAO/Al electrode was fabricated by a second step anodization, followed by electrodeposition and its electrochemical behavior was investigated in detail. The cyclic voltammetry results indicated that the SnNR/AAO/Al electrode exhibited efficient electrocatalytic activity toward reduction of ONB in the acidic solution. It provides an appreciable improvement of reduction peak for ONB at-0.721 V.Furthermore, various kinetic parameters such as transfer electron number, transfer proton number and standard heterogeneous rate constant were calculated from the scan rates.The electrocatalytic behavior was further exploited as a sensitive detection scheme for the ONB determination by differential pulse voltammetry. Under the optimized conditions, the concentration range and detection limit are 0.1-100 μmol/L and 0.05 μmol/L, respectively,for ONB. The analytical performance of this modified sensor has been evaluated for detection of real sample such as river water and recovery of ONB was achieved all-out up to102.3% under standard addition method.展开更多
CNT-added surface treatment (CAST) is a newly developed technology that incorporates single-walled carbon nanotubes (SWCNTs) into a metal surface through alternate current electrolysis using a dispersion of SWCNTs in ...CNT-added surface treatment (CAST) is a newly developed technology that incorporates single-walled carbon nanotubes (SWCNTs) into a metal surface through alternate current electrolysis using a dispersion of SWCNTs in an alkaline aqueous solution. We apply this method to Al-plates and characterize their surface morphology and components through scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. After CAST processing, protrusion structures of Al-oxide containing SWCNTs are formed on the surface of the Al-plate, and the surface morphology differs significantly from that of the surface of Al films treated through conventional anodic oxidation. The height and spacing of the protrusion structures formed on the surface of the CAST-treated Al-plates are 100 - 200 nm and 50 - 100 nm, respectively. In addition, we investigate the formation mechanism of the protrusion structure by applying a DC voltage between the working electrode (Al-plate) and a counter electrode immersed in a dispersion of SWCNTs in an alkaline aqueous solution. Comparing the Al-plate surface after treatment under both current directions, we propose a model for the formation process of protrusion structures containing SWCNTs based on catalyst surface etching.展开更多
Silver nanorod arrays have been fabricated by alternat-ing current（AC） and pulsed direct current（DC） electrodeposition in porous anodic aluminum oxide（AAO） templates with controlled pore diameters of 19,38,and 6...Silver nanorod arrays have been fabricated by alternat-ing current（AC） and pulsed direct current（DC） electrodeposition in porous anodic aluminum oxide（AAO） templates with controlled pore diameters of 19,38,and 65 nm,respectively.The variation of their optical absorption properties with the incident angle and the nanorods length（corresponding to the electrodeposition time） has been investigated.Optical absorption spectra show that the posi-tion of longitudinal surface plasmon resonance（LSPR） peak has a small blueshift with the increase of incident angle of the excitation light.While the aspect ratio of the nanorods increases,the position of LSPR peak first redshifts and then blueshifts to a certain wave-length.Furthermore,the position of LSPR peak can be tuned,ranging from 550 nm to 900 nm,which makes it possible to cou-ple various wavelength of excitation source to assist radiative en-ergy transfer to the acceptor.展开更多
文摘Zirconium oxide nanoparticles with 0.4 wt.%and 0.8 wt.%are incorporated into the Al-0.65 Mg-0.05 Ga-0.15 Sn(wt.%)alloy anode(base alloy)in order to improve the performance of the resulting anodes.Electrochemical characterization of the reinforced alloys was done by potentiodynamic polarization,electrochemical impedance spectroscopy and galvanostatic discharge and corrosion behavior was evaluated using self-corrosion rate and hydrogen evolution in 4 mol/L KOH solution.The surface morphology of the alloys was also studied using field emission scanning electron microscope(FESEM).The obtained results indicate that the base alloy shows high corrosion rate in 4 mol/L KOH solution by releasing 0.47 m L/(min·cm^2)hydrogen gas,whereas the alloy containing 0.8 wt.%Zr O2 provides the lowest hydrogen evolution rate by releasing 0.32 m L/(min·cm^2)hydrogen gas.Furthermore,by increasing zirconium oxide nanoparticles,the corrosion current density of the aluminum anodes is decreased and their corrosion resistance increases significantly compared to the base alloy in alkaline solution.In addition,nanometer-sized zirconium oxide incorporated anodes exhibit the improved galvanic discharge efficiencies,so that 0.8 wt.%nano-zirconium oxide incorporated base alloy displays the highest power density and anodic utilization compared with the others in 4 mol/L KOH solution.
文摘ZnFe 2O 4 and ZnFe 2O 4 based materials were tested to obtain the electrical conductivity and corrosion resistance in melting bath for aluminum electrolysis. The results proved that adequate additives, such as Ni 2O 3 CuO, Cu, ZnO and CeO 2 would increase the electrical conductivity, and the ZnFe 2O 4 based anodes with these additives were of good corrosion resistance. The current density on anode, the mole ratio of NaF/AlF 3 (MR) and the content of alumina in the bath effect the anode corrosion rate in different way.
文摘A systematic laboratory study was conducted on current efficiency and corrosion obtained in cryolite-alumina melts with SnO2-Sb203-CuO ceramic inert anodes. The current efficiency （CE） was determined by measuring the total amount of oxygen evolved at the anode and was found to be ~ 95%. The influence of operating parameters （inter-elec- trode distance, temperature and current density） was evaluated. The quantitative interdependencies as well as the ranges of CE optima[ values were established （2-3 cm, 940-960 ℃ and 0.7-0.8 A.cm 2）. The corrosion process of these anodes was evaluated by the mass loss method. The evaluation also took care of the corrosion data, as the prob- lem of the anode corrosion appeared to be the main obstacle for the use of those anodes in the commercial cells.Low-ering of the ACD up to 2 cm did not aggravate anode corrosion.
基金Project(2010AA065201)supported by the High Technology Research and Development Program of ChinaProject(2013zzts038)supported by the Fundamental Research Funds for the Central Universities of ChinaProject(ZB2011CBBCe1)supported by the Major Program for Aluminum Corporation of China Limited,China
文摘Numerical simulations of gas–liquid two-phase flow and alumina transport process in an aluminum reduction cell were conducted to investigate the effects of anode configurations on the bath flow, gas volume fraction and alumina content distributions. An Euler–Euler two-fluid model was employed coupled with a species transport equation for alumina content. Three different anode configurations such as anode without a slot, anode with a longitudinal slot and anode with a transversal slot were studied in the simulation. The simulation results clearly show that the slots can reduce the bath velocity and promote the releasing of the anode gas, but can not contribute to the uniformity of the alumina content. Comparisons of the effects between the longitudinal and transversal slots indicate that the longitudinal slot is better in terms of gas–liquid flow but is disadvantageous for alumina mixing and transport process due to a decrease of anode gas under the anode bottom surface. It is demonstrated from the simulations that the mixing and transfer characteristics of alumina are controlled to great extent by the anode gas forces while the electromagnetic forces(EMFs) play the second role.
基金financially supported by the National Natural Science Foundation of China (No.51271036)
文摘AlNbO_4,as lithium-ion batteries（LIBs） anode,has a high theoretical capacity of 291.5 m Ah g^-1.Here,AlNbO_4 anode materials were synthesized through a simple solid-state method.The structure,morphology and electrochemical performances of AlNbO4 anode were systematically investigated.The results show that AlNbO4 is monoclinic with C2/m space group.The scanning electron microscopy（SEM） and transmission electron microscopy（TEM） characterizations reveal the AlNbO_4 particles with the size of 100 nm^–2 lm.As a lithium-ion batteries anode,AlNbO4 delivers a high reversible capacity and good rate capability.The discharge capacity is as high as 151.0 m Ah g^-1 after 50 charge and discharge cycles at 0.1 C corresponding to capacity retention of 90.7 %.When the current density increases to 5.0C,AlNbO4 anode displays reversible discharge capacity of 73.6 m Ah g^-1 at the50 th cycle.
基金National Natural Science Foundation of China(Nos.51204147,51274175,51574206,51574207)Program for International S&T Cooperation Projects of China(No.2014DFA50320)+1 种基金Program for International S&T Cooperation Projects of Shanxi Province(No.201381017)Technological Projects of Shanxi Province(No.20150313002-3)
文摘According to dynamics of coupled galvanic anode with carbon steel,the integral of galvanic current vs.time is approximately equal to actual current capacity of galvanic anode.Galvanic current of cast aluminum galvanic anode coupled with carbon steel is tested in3.5%NaCl solution and ambient temperature.Rapid evaluation the performance of galvanic anode using galvanic current is feasible,and the test time is20min.The galvanic current is used to select aluminum galvanic anodes in oil brine,and then test the galvanic anodes with impressed current test method.The result shows,the performance of galvanic anodes degrads in oil brine,but has not much difference in the two media to the preferable anodes,and the optimal galvanic anode is gained.
基金Project supported by the Open Fund of the State Key Laboratory of Powder Metallurgy,China
文摘In order to evaluate the electrochemical properties of aluminum alloy anode under high current densities in alkaline electrolyte, the galvanostatic discharge, potentiodynamic polarization and hydrogen evolution tests of three experimental Al?Mg?Sn?In?(Ga) alloys were performed. The results show that the alloying element gallium improves the working potentials of experimental Al?Mg?Sn?In alloys under different discharge current densities. The average working potentials of the alloys containing gallium can reach?1.3 V under current density ranging from 650 to 900 mA/cm2, while those of alloy without Ga are only?1.0 V. Such phenomenon is attributed to the solid solution which can form amalgam with aluminum matrix. Such an amalgam can form the hydrolyzed species during the discharge process and lead to the corrosion infiltrating into aluminum matrix.
基金financially supported by the Program of the National Natural Science Foundation of China(Grant No.52371055)the Young Elite Scientist Sponsorship Program Cast(Grant No.YESS20200139)the Basic Scientific Research Project of Liaoning Provincial Department of Education(Grant No.JYTMS20230618)。
文摘The effect of intermetallic particles on the corrosion of 6061 aluminum alloy and its coating used in semiconductor processing systems was systematically studied via liquid and gas experiments and micromorphology characterization.The results revealed that a huge difference of corrosion resistance between imported and domestic 6061 aluminum alloys in HCl solution and gas acid mist experiments mainly was attributed to the different size and amount of Al_(15)(Fe,Mn)_(3)Si_(2).The corrosion resistance of domestic 6061 alloy in dry/wet semiconductor electronic special gas environments was worse than that of imported aluminum alloy,and there are great differences in the corrosion mechanism of 6061 alloy caused by the second phase in the two dry/wet environments.And the corrosion resistance of the hard anodized alumina film was closely related to the microscopic morphology of holes.The vertical and elongatedα-Al_(15)(Mn,Fe)_(3)Si_(2) phase was formed in the rolled aluminum alloy that has been rolled perpendicular to the surface of the substrate.Compared to the horizontal long hole,the longitudinal long holes generated by the verticalα-Al_(15)(Mn,Fe)_(3)Si_(2) phase will enable the corrosive medium to reach the substrate rapidly,which significantly weakens the corrosion resistance of the hard anodized film.
基金supported by the Program of the National Natural Science Foundation of China(Grant No.52371055)the Young Elite Scientist Sponsorship Program Cast(Grant No.YESS20200139)+1 种基金the Basic Scientific Research Project of Liaoning Provincial Department of Education(Grant No.JYTMS20230618)Special thanks are due to the instrumental analysis from the Analytical and Testing Centre,Northeastern University.
文摘A principle was proposed for designing a method to seal anodized aluminum used in semiconductor processing apparatuses.Thermodynamic calculations and Fick’s second law were used to reveal trends in the metal ion deposition,deposition product stability,vapor pressures of halides for selected metal ions,the holding temperature,and time.Interactions between ion concentrations and the sealing temperature were also revealed.According to the design principles,anodized aluminum dipped in 1 mM Cr^(3+)ion solution and steam-sealed for 18 h exhibited the highest corrosion resistance when exposed to 5 wt.%HCl solution and HCl gas,verifying the designed results.
基金supported by Natural Sciences and Engineering Research Council of Canada (NSERC)Canada Research Chair (CRC) Program+1 种基金National Nature Science Foundation of China (No.51474255)Open-End Fund for the Graduate Student Research Innovation Project of Hunan Province (No. 150140008)
文摘The aluminum-air battery is considered to be an attractive candidate as a power source for electric vehicles(EVs) because of its high theoretical energy density(8100 Wh kg^(-1)), which is significantly greater than that of the state-of-the-art lithium-ion batteries(LIBs). However,some technical and scientific problems preventing the large-scale development of Al-air batteries have not yet to be resolved. In this review, we present the fundamentals, challenges and the recent advances in Al-air battery technology from aluminum anode, air cathode and electrocatalysts to electrolytes and inhibitors. Firstly, the alloying of aluminum with transition metal elements is reviewed and shown to reduce the selfcorrosion of Al and improve battery performance. Additionally for the cathode, extensive studies of electrocatalytic materials for oxygen reduction/evolution including Pt and Pt alloys, nonprecious metal catalysts, and carbonaceous materials at the air cathode are highlighted.Moreover, for the electrolyte, the application of aqueous and nonaqueous electrolytes in Al-air batteries are discussed. Meanwhile, the addition of inhibitors to the electrolyte to enhance electrochemical performance is also explored. Finally, the challenges and future research directions are proposed for the further development of Al-air batteries.
基金supported by the National Basic Research Program of China (No. 2015CB251100)the Program for New Century Excellent Talents in University (NCET-13-0033)+1 种基金the Beijing Co-construction Project (No. 20150939014)the Beijing Higher Institution Engineering Research Center of Power Battery and Chemical Energy Materials
文摘Aluminum(Al) metal has been regarded as a promising anode for rechargeable batteries because of its natural abundance and high theoretical specific capacity. However, rechargeable aluminum batteries(RABs) using A1 metal as anode display poor cycling performances owing to interface problems between anode and electrolyte. The solid-electrolyte interphase(SEI) layer on the anode has been confirmed to be essential for improving cycling performances of rechargeable batteries. Therefore, we immerse the Al metal in ionic liquid electrolyte for some time before it is used as anode to remove the passive film and expose fresh Al to the electrolyte. Then the reactions of exposed Al, acid, oxygen and water in electrolyte are occurred to form an SEI layer in the cycle. Al/electrolyte/V_2 O_5 full batteries with the thin, uniform and stable SEI layer on Al metal anode perform high discharge capacity and coulombic efficiency(CE). This work illustrates that an SEI layer is formed on Al metal anode in the cycle using a simple and effective pretreatment process and results in superior cycling performances for RABs.
基金supported by National Natural Science Foundation of China(Grant No.51872196)China Postdoctoral Science Foundation Special Fund for the Third Batch(Grant No.2021TQ0200),China Postdoctoral Science Foundation Project for the 71st Batch(Grant No.2022M712034)+1 种基金the Carbon Peaking and Carbon Neutrality Technology Innovation Special Fund of Jiangsu Province(Grant number:BE2022041)Open Foundation of Shanghai Jiao Tong University Shaoxing Research Institute of Renewable Energy and Molecular Engineering(Grant number:JDSX2022023)。
文摘Aluminum(Al),the most abundant metallic element on the earth crust,has been reckoned as a promising battery material for its the highest theoretical volume capacity(8046 mAh cm^(-3)).Being rechargeable in ionic liquid electrolytes,however,the Al anode and battery case suffer from corrosion.On the other hand,Al is irreversible in aqueous electrolyte with severe hydrogen evolution reaction.Here,we demonstrate a water-in-salt aluminum ion electrolyte(WISE)based on Al and lithium salts to tackle the above challenges.In the WISE system,water molecules can be confined within the Li^(+)solvation structures.This diminished Al^(3+)-H_(2)O interaction essentially eliminates the hydrolysis effect,effectively protecting Al anode from corrosion.Therefore,long-term Al plating/stripping can be realized.Furthermore,two types of high-performance full batteries have been demonstrated using copper hexacyanoferrate(CuHCF,a Prussian Blue Analogues)and LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM)as cathodes.The reversibility of Al anode laid the foundation for low cost rechargeable batteries suffering for large-scale energy storage.Broader context:Al batteries are expected to become a safe and sustainable alternative to lithium batteries.For decades,chase for a feasible Al secondary battery has not been successful.The key challenge is to find suitable cathode and electrolyte materials,together with which Al anode battery can function reversibly.Currently,fatal drawbacks have impeded the practical application of Al metal batteries(AMBs),such as sustained corrosion of Al anode and battery case in ionic liquid electrolytes,irreversibility issues as well as severe hydrogen evolution reaction during cycling in aqueous electrolyte.Therefore,electrolyte and their electrochemical kinetics play a vital role in the performance and environmental operating limitations of high-energy Al metal batteries.In this work,we demonstrate a nearly neutral Al ion water-in-salt electrolyte(WISE)to tackle the above challenges.The WISE shows excellent stability in the open atmosphere.The distinct solvation-sheath structure of Al^(3+)in the WISE system would protect Al metal anodes from corrosion and eliminate hydrogen evolution reaction effectively,further promoting the reversibility of Al metal anodes with dendrite-free morphology.Moreover,such a WISE exhibits superior compatibility with LiNi_(0.3)Co_(0.3)Mn_(0.3)O_(2)(NCM)and copper hexacyanoferrate(CuHCF)cathodes and long-term stabilities with high coulombic efficiency(CE)can be attained for full batteries with the WISE.The approach in this study can furnish an opportunity to develop reversible AMBs and lay the foundation for other potential multivalent-metalbased secondary batteries suffering from interface passivation and poor reversibility,which suggest the promise of multivalent metal batteries and their applications in large-scale energy storage.
基金supported the National Natural Science Foundation of China(Grant No.62101296 and 52303335)the China Postdoctoral Science Foundation(2023M730099)+1 种基金the Natural Science Foundation of Shaanxi Province(Grant No.2021JQ-756)the Special Scientific Research Plan of the Education Department of Shaanxi Province(Grant No.22JK0323).
文摘The growing market for electric vehicles and upcoming grid-scale storage systems is spurring the development of renewable energy storage technologies.Rechargeable aqueous aluminum-ion batteries(AIBs)are considered ideal for large-scale energy storage because of their cost-competitiveness,simplicity of manufacturing,eco-friendliness,high intrinsic safety,and high theoretical energy density.In addition,AIBs use aluminum as a raw material,which is the most abundant metal in the Earth’s crust.However,metallic aluminum anodes exhibit poor thermodynamic stability in solutions because of self-corrosion,surface passivation,and hydrogen precipitation reactions.These factors considerably limit their electrochemical performance and impede the further development of AIBs.This review discusses the recent advances in the anode materials used in AIBs.We first briefly describe the energy storage mechanisms and challenges faced by various AIB anodes,including aluminum metal anodes,alloy anodes,and intercalated anodes.Subsequently,we summarize the interactions between the structures and reaction mechanisms of different anode materials,which have been used to prevent the passivation and corrosion of metallic aluminum anodes.Finally,we present the key challenges and future research perspectives for optimizing aluminum anodes to enhance the performance of AIBs.
基金Supported by the National Natural Science Foundation of China (No. 50271046).
文摘Fe nanowire arrays are prepared by electrodeposition in porous anodic aluminum oxide template from a composite electrolyte solution. These nanowires have an uniform diameter of approximate 25 nm and a length in excess of 2.5 μm. The micrographs and crystal structures of Fe nanowires are studied by transmission electron microscopy (TEM), selected-area electron diffraction (SAED), and X-ray diffraction(XRD). It is found that each nanowire is essentially a single crystal and has a different orientation in each array. Hysteresis loops of Fe nanowire array show that its easy magnetization direction is perpendicular to the sample plane.
基金This work has been carried out with the support of The Chinese Postdoctoral Science FundThe Special Funds for the Major State Basic Research Projects G19990650.
文摘The rare earth sealing procedure of the porous film of anodized aluminum alloy 2024 was studied with the fieldemission scanning electron microscope (SEM) and X-ray energy dispersive spectroscopy (EDS). The results show thatRE solution can form cerium oxide/hydroxides precipitation in the pores of the anodized coating at the beginning ofsealing. At the same time, the spherical deposits formed on the surface of the anodized coating created a barrierto the precipitation of RE solution in the pores. When the pore-structured anodizing film is covered all with thespherical deposits, RE conversion coating will form on the surface of the anodized coating. The reaction of thecoating formation was investigated by employing cyclic voltammetry. The results indicate that accelerator H2O2 actsas the source of O2 by carrying chemical reaction in course of coating formation. In the mean time, it maybe carrieselectrochemical reaction to generate alkaline condition to accelerate the coating formation. The porous structure ofthe film is beneficial to the precipitation of the cerium hydroxides film.
文摘Aluminum specimens were anodized in a sulfuric acid bath, thensilver was electrodeposited in pores of the anodized aluminum byusing alternating current. The anodized aluminum with depositedsilver was tested for its antibacterial performance. The results showthat the antibacterial rates of the specimens are above 95/100against the growth of E. coli, P. Aeruginasa, S. faecalis and S.aureus. The morphology of the silver in pores of anodized aluminum ischaracterized by transmission electron microscopy, and themicrographs indicate that silver is assembled in the form ofnanowires with a diameter of 10 nm or 25 nm. The nanowires have astructure of parallel bright stripes alternating with parallel darkstripes.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51025101,51101095,61434002,11274214,and 51301099)the Program of"One Hundred Talented People"of Shanxi Province,China
文摘A new Fe Pt nanostructure with stripe-like patterns has been prepared by direct current（DC） magnetron sputtering on anodic aluminum oxide（AAO） templates. AAO templates anodized under low voltages（7 V） demonstrate self-organized,maze-like patterns, different from the conventional porous structures obtained at high voltages. Fe Pt thin films deposited on such templates tend to replicate the morphology of the templates. Although there is no obvious spatial ordering, the dimensions of the Fe Pt nano-stripes are highly uniform, due to the constrained growth along the transverse direction of the AAO pattern. The magnetic properties are strongly influenced by this unique morphology. While continuous films demonstrate strong exchange coupling, the dominant interaction in Fe Pt nano-stripes with the same nominal thickness is magnetostatic. The morphology also dictates the magnetization reversal behaviors, with thin films dominated by domain nucleation; while nano-stripes incline to reverse their magnetization by spin rotation. Our work demonstrates that selforganized AAO templates can be used to control the morphology and magnetic behavior of Fe Pt materials.
基金CSIR (09/0810 (0021)/ 2012-EMR-I), Periyar University for providing fundUGC networking resource center for providing visiting fellowship
文摘A simple, cost effective and rapid electrochemical method has been developed for the determination of micro level ortho nitrobenzaldehyde（ONB） based on outstanding properties of modified aluminum electrode tin nanorods/anodic aluminum oxide/aluminum（SnNR/AAO/Al） for the first time. The SnNR/AAO/Al electrode was fabricated by a second step anodization, followed by electrodeposition and its electrochemical behavior was investigated in detail. The cyclic voltammetry results indicated that the SnNR/AAO/Al electrode exhibited efficient electrocatalytic activity toward reduction of ONB in the acidic solution. It provides an appreciable improvement of reduction peak for ONB at-0.721 V.Furthermore, various kinetic parameters such as transfer electron number, transfer proton number and standard heterogeneous rate constant were calculated from the scan rates.The electrocatalytic behavior was further exploited as a sensitive detection scheme for the ONB determination by differential pulse voltammetry. Under the optimized conditions, the concentration range and detection limit are 0.1-100 μmol/L and 0.05 μmol/L, respectively,for ONB. The analytical performance of this modified sensor has been evaluated for detection of real sample such as river water and recovery of ONB was achieved all-out up to102.3% under standard addition method.
文摘CNT-added surface treatment (CAST) is a newly developed technology that incorporates single-walled carbon nanotubes (SWCNTs) into a metal surface through alternate current electrolysis using a dispersion of SWCNTs in an alkaline aqueous solution. We apply this method to Al-plates and characterize their surface morphology and components through scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. After CAST processing, protrusion structures of Al-oxide containing SWCNTs are formed on the surface of the Al-plate, and the surface morphology differs significantly from that of the surface of Al films treated through conventional anodic oxidation. The height and spacing of the protrusion structures formed on the surface of the CAST-treated Al-plates are 100 - 200 nm and 50 - 100 nm, respectively. In addition, we investigate the formation mechanism of the protrusion structure by applying a DC voltage between the working electrode (Al-plate) and a counter electrode immersed in a dispersion of SWCNTs in an alkaline aqueous solution. Comparing the Al-plate surface after treatment under both current directions, we propose a model for the formation process of protrusion structures containing SWCNTs based on catalyst surface etching.
基金Supported by the National Natural Science Foundation of China (10874134)
文摘Silver nanorod arrays have been fabricated by alternat-ing current（AC） and pulsed direct current（DC） electrodeposition in porous anodic aluminum oxide（AAO） templates with controlled pore diameters of 19,38,and 65 nm,respectively.The variation of their optical absorption properties with the incident angle and the nanorods length（corresponding to the electrodeposition time） has been investigated.Optical absorption spectra show that the posi-tion of longitudinal surface plasmon resonance（LSPR） peak has a small blueshift with the increase of incident angle of the excitation light.While the aspect ratio of the nanorods increases,the position of LSPR peak first redshifts and then blueshifts to a certain wave-length.Furthermore,the position of LSPR peak can be tuned,ranging from 550 nm to 900 nm,which makes it possible to cou-ple various wavelength of excitation source to assist radiative en-ergy transfer to the acceptor.
